If it takes 5 machines 5 minutes to make 5 widgets, how many minutes does it take 100 machines to make 100 widgets? 

5 Minutes


When we’re presented with a problem, our brains shunt the cognitive work to either of two pathways, called system 1 and system 2.
































When we use system 1 processing, we’re making use of patterns, experience, intuition, and heuristics to guide our problem solving and decision making. System 1 is efficient, easy, and accurate – about 90 percent of the time.
That 10 percent is a real bummer, though, especially when the stakes are high. To overcome the intrinsic error rate associated with system 1, we need to shift to system 2, which makes use of logic and analysis to guide our decisions. This is the problem-solving process that we use for problems that seem unfamiliar. System 2 is time consuming and cognitively burdensome, which explains why novices get cognitively overloaded so easily. But it’s also less bias-prone than system 1, so it works well for increasing diagnostic accuracy and improving clinical reasoning. 
We can’t know prospectively which 10 percent of system 1 decisions are erroneous, so we have to be cognizant always of how we’re making decisions and try to engage system 2 thinking. The easiest way to encourage rational override of system 1 is to force ourselves to consider alternative diagnoses and worst-case scenarios.

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Lily pads on the surface of a lake double in surface area every 24 hours. If it takes 40 days for the lily pads to cover the lake completely, how many days does it take for half of the lake to be covered?

STOP. Before you commit to your answer, take a moment to consider how you arrived there. Did you apply a heuristic, or did you set up an algebra problem in your head? Take a brief time out to check your work. Does the math make sense?